Rapid determination of benzo[a]pyrene by membrane enrichment coupled with solid‐phase constant‐wavelength synchronous fluorescence spectrometry

Normal methods for benzo[a]pyrene (BaP) determination, including gas chromatography–mass spectrometry and liquid chromatography with fluorescence detection, involve expensive instruments and complex separation and purification processes. Based on membrane enrichment, coupled with solid‐phase constant‐wavelength synchronous fluorescence spectrometry, a simple, fast, sensitive method was proposed for the determination of BaP in water samples. A Nylon membrane was used as the solid‐phase extraction material for enrichment. After enrichment, a constant‐wavelength synchronous fluorescence spectrum was scanned directly on the membrane‐concentrated BaP without elution. Spectral measurement and enrichment conditions were optimized. Under optimum conditions, when using 150 mL sample solutions, the relationship between fluorescence intensity and BaP concentrations in the 0.05–10.00 μg L^–1 range could be fitted by binomial function with an R² value of 0.9973. Limit of detection (LOD) was calculated to be 0.0137 μg L^–1. The volume of the sample solution was increased to 1000 mL to test if the method could be applied to determine lower BaP concentrations. A linear relationship still existed in the range 2.0–20.0 ng L^–1 BaP with an R² value of 0.9895, and a LOD of 2.4 ng L^–1. The method was also used to measure the BaP concentration in several natural water samples, and recoveries were in the 90–110% range with relative standard deviations (RSDs) in the 0.58–7.93% range. Copyright © 2016 John Wiley & Sons, Ltd.